Mail problem-Relay access denied-maybe saslauth???

I have a problem with mail server....
When i try to send mail with webmail it all works fine, but when i send it via
Outlook i get error:

Code:

Your message did not reach some or all of the intended recipients.
Subject: xcscyxc
Sent: 9.1.2007 16:30
The following recipient(s) could not be reached:
'[email protected]' on 9.1.2007 16:30
554 5.7.1 <[email protected]>: Relay access denied

If i set "my outgoing server needs authentication" i need to enter password from my user but that doesnt work. Do i need some other password?

I think that my sasl auth is not configured for users of my ISPconfig...
.and one more problem...

For [email protected] user I stoped reciving mail and I can't send mail from that(using webmail- when i send a mail to myself it just says: Mail sent seccesfully. but when i check mail I dont get nothing)..

Is this your local router address? It should point to an upstream DNS server. That could be your local ADSL router (if your working on a home LAN) or your provider one. You can also specify multiple (max three) IP addresses here of valid/working DNS servers.